For what type of writing was Mr. Asimov most famous?

While Asimov did write some juvenile fiction, including stories aimed at younger audiences, it is not the genre for which he is best known. His most significant and influential works are largely targeted at adult readers, particularly in the realms of science fiction and popular science.

Asimov did not primarily write in the mystery genre. Although he wrote a few mystery stories, such as his "Black Widower" series, these works do not constitute the majority of his literary output or his most recognized contributions. His legacy is firmly rooted in science fiction rather than mystery.

Asimov was indeed a prolific writer of popular science and made complex scientific concepts accessible to the general public. However, it is his science fiction writing that truly defines his legacy and distinguishes him among authors. His science fiction narratives often incorporated scientific principles, showcasing his ability to blend both genres.